client library only sets mysql->insert_id when query returned
no recordset. So the embedded library should behave the same way


libmysqld/lib_sql.cc:
  Bug #26921 Problem in mysql_insert_id() Embedded C API function.
  
  only set 'affected_rows' and 'insert_id' fields when query
  didn't return a recordset
tests/mysql_client_test.c:
  Bug #26921 Problem in mysql_insert_id() Embedded C API function.
  
  testcase added